Friday, April 12, 2024

The American Dipper Nest-Building Story!


Back in the beginning of March a pair of American Dippers built a nest on the bridge pillar featured in the photos below.  About three weeks after they built the nest it was totally gone!!! I suspected that a pair of Ravens had destroyed the nest, in their attempt to eat the eggs.  Whether it was Ravens or not, I'll never know.  But the river between the pillar and the shoreline has been way too high and fast for a person to reach the Dipper nest. So it was probably the Ravens. Surprisingly, three days after the nest was possibly removed by the Ravens, the Dippers started building a NEW nest!  In six days time, their new nest was completely built!!!  It has been in place now for seven more days!  Hopefully the Dippers will be able to raise some young in this nest! Fingers crossed! I'll keep you posted. Below are photos of the nest as it was being constructed over six consecutive days!

American Dipper Nest - Day 1

The following information about American Dipper nests, nestlings, and fledglings is from the Cornell website at https://birdsoftheworld.org. The text does not correspond with the photos, but I wanted to post what the raising of a young American Dipper entails! For more information on the actual construction of the nest, check out my blog, "Spring Sightings", on March 31, 2023.

"The nest is a 2-part domed or ball-like structure with side entrance. Canopy of dome may overhang entrance hole to keep out water. Outer shell of moss with small amounts of interwoven grass (both stems and roots) and leaves. Inner chamber globular with woven cup or pad, composed of grass and leaves, sometimes bark.

American Dipper Nest - Day 2

Nest is well-insulated; seems adapted to control inside temperature (warm or cool, as necessary) and to keep inside dry. Thick outside mossy shell (3–5 cm thick) absorbs moisture; inside coarse grasses resist wetting.

American Dipper Nest - Day 3

Between completion of nest-building and laying of the first egg, 6–15 d lapse. Usually lays 1 egg/day, for a total of 4-5 eggs per clutch.

American Dipper Nest - Day 4

Incubation period 14–17 d . Female develops a large brood patch and does all incubation. Male carries food to female on nest, but she also feeds herself . Baby birds are altricial, and born naked except for sparse down. Chicks stay in nest about 25 d, sometimes longer. Both parents feed the chicks.

Video of an American Dipper compacting the moss in the walls of its nest!

American Dipper Nest - Day 5

Female broods regularly for about 1 week after hatching and continues to about day 16. During first few days, female broods for 5–61 min periods, leaves nest for 8–22 min periods. By day 16, nestlings nearly fill nest, so female enters nest with great difficulty and remains only a short time; only 2 brooding periods of 6 min each. Female enters nest by crawling over young birds; turns, stays in rear of nest. When male feeds young, female remains in back and young protrude heads from beneath her breast to receive food. Both parents deliver food to nestlings, the male more frequently while the female broods.

Completed American Dipper Nest - Day 6

Within the first hour after fledging, young bird moves around and takes quick steps. Starts dipping; frequency varies but increases when parents approach. Enters water, if shallow, and bathes by fluttering wings; can swim in water too deep for wading. May briefly poke head under water as if looking for food; picks at lichens and moss on rocks. Newly fledged young is active for about 1 h after leaving nest, then tires and stands still or preens. If not disturbed, typically remains within 12 m of nest. If young slips into water, it can use wings or feet to crawl out. Full flight not observed first day out of nest, but fledglings are able to flutter several meters back up to nest ledge. Parents feed young for widely varying periods (4–35 d) after leaving nest. Upon achieving independence, juveniles disperse."

Two Dipper nestlings in 2020

A Note on Nest Watching

Nest watching is fascinating but you need to be careful not to disturb the nesting birds. You also do not want to attract the attention of other birds. If you stay and watch young birds in a nest for too long, you may be noticed by their predators. Here are a few of my suggestions:

Do not check the nest every day. Wait at least three days between observations.

Do not observe the nest for more than a minute, unless at a good distance.

Conceal yourself if possible, so that the nesting birds are not disturbed, and that predators don't watch you watching.

Here are a few additional tips from the Cornell Ornithology Lab:

"Do not check in the early morning. Most birds lay their eggs in the early morning so plan on visiting nests in the late morning or afternoon. Also, most adults will temporarily leave the nest when you are near, and eggs and young nestlings can become cold quickly if left alone in the early morning.

Avoid nests during the first few days of incubation.

Do not approach nests when young are close to fledgling. When the young are disturbed during this stage, they may leave the nest prematurely. Young that fledge prematurely usually do not stay in the nest despite attempts to return them, and their survival rates away from or outside the nest are low.

When young birds are fully feathered and very alert, only observe the nest from a distance.

Avoid nests during bad weather. If it is cold, damp, or rainy, postpone checking nests until another day. Checking nests during this time can be very stressful for birds.

Do not check nests at or after dusk, when females may be returning to the nest for the night. The exception to this would be owls, which typically leave the nest at dusk."

American Robin Nest

 A Note on Nest Collecting

To my annoyance people often take the Dipper's nest mentioned above, usually after the nesting season. If they left the nest, the Dippers would possibly reuse parts of it, or "refurbish" it and reuse it the following year. What most people don't know is that it is illegal to collect migratory bird species nests. Dippers are NOT migratory birds, but I always think it is better to leave nests alone. The following information about Migratory Bird Nests is from the Fish & Wildlife Service at https://www.fws.gov/story/bird-nests.

"Most bird nests are protected under the Migratory Bird Treaty Act (MBTA). The Migratory Bird Treaty Act of 1918 (16 U.S.C. 703-712) implements four international conservation treaties that the U.S. entered into with Canada in 1916, Mexico in 1936, Japan in 1972, and Russia in 1976. It is intended to ensure the sustainability of populations of all protected migratory bird species. This law says: “No person may take (kill), possess, import, export, transport, sell, purchase, barter, or offer for sale, any migratory bird, or the parts, nests, or eggs of such bird except as may be permitted under the terms of a valid permit…” Under the MBTA it is illegal to destroy a nest that has eggs or chicks in it or if there are young birds that are still dependent on the nest for survival. It is also illegal for anyone to keep a nest they take out of a tree or find on the ground unless they have a permit to do so issued by the U.S. Fish and Wildlife Service."

Wild Turkeys (3 females) - Meleagris gallopavo

New Arrivals!

It's Springtime and migratory birds are arriving every day, and wildflowers are blooming! Almost every day something surprises me, like these three American Turkeys in my neighbors' yard!  We have never had turkeys in our neighborhood! They usually inhabit the foothills! I was surprised how camouflaged they were in the blackberry thicket. It will be interesting to see if they stick around!

Although Wild Turkeys usually inhabit the local foothills, they have been documented in the Sierra up to 10,000' in elevation! They are not native to Calfornia but were introduced from Mexico in the early 1900's. They were also introduced as late as 1997 into the higher elevations of Sierra, Nevada, and Placer Counties, by the CA. Dept. of Fish and Wildlife, the U.S. Forest Service, and the National Wild Turkey Federation. This has proven to be a detrimental introduction, as the turkeys compete with the native grouse and quail. They do not stay during the winter snows, so they must walk quite a distance to their winter habitat in the foothills! Perhaps the drier, hotter, drought years have driven them to higher elevations. The following information is from the Cornell website allaboutbirds.org.

"Wild Turkeys get around mostly by walking, though they can also run and fly—when threatened, females tend to fly while males tend to run. At sundown turkeys fly into the lower limbs of trees and move upward from limb to limb to a high roost spot. They usually roost in flocks, but sometimes individually. Courting males gobble to attract females and warn competing males. They display for females by strutting with their tails fanned, wings lowered, while making nonvocal hums and chump sounds. Males breed with multiple mates and form all-male flocks outside of the breeding season, leaving the chick-rearing to the females, The chicks travel in a family group with their mother, often combining with other family groups to form large flocks of young turkeys accompanied by two or more adult females."

White-crowned Sparrow (male) - Zonotrichia leucophrys

Recently arrived from the foothills or perhaps Mexico! He will mate and raise his young here in our neighborhood.

Meadowlark (adult) - Sturnella neglecta

Recently arrived from the foothills or the central valley of California! This Meadowlark won't stay here and nest.  It will probably migrate over to Sierra Valley to raise its young.

Black-headed Grosbeak (male) - Pheucticus melanocephalus

Recently arrived from Mexico! These lovely Grosbeaks will stay and raise their young here, or perhaps at a little higher elevation in the area.

Brewer's Blackbird (male-female) - Euphagus cyanocephalus

Recently arrived from the foothills or central valley of California! These Blackbirds raise their young right in our neighborhood every year!

Sicklepod Rock Cress - Boechera sparsiflora

These lovely, pink Sicklepod Rock Cress flowers popped up this week! They are about two feet tall and are one of the early bloomers in our area.

Oregon Grape - Berberis aquifolium

Oregon Grape is an early blooming shrub that is in full bloom right now.
It attracts lots of native pollinators.

Western Rue Anemone - Enemione occidentale

These delicate little flowers can be found on damp shady slopes. 
Currently there are lots of them growing on the forest floor.

Grand Hound's Tongue - Adelinia grandis

The name Grand Hound's Tongue, refers to the large pointed leaves of this plant.

What's happening on the Canyon Creek Trail?

What's happening in the Lakes Basin?

Check back next week for the answers to these questions and more.
Your questions and comments are greatly appreciated.  Please email me at northyubanaturalist@gmail.com.

Friday, April 5, 2024

The Blooming Foothills!

Bird's-eye Gilia and Goldfields 
Gilia tricolor - Lasthenia californica

This week we had three gloriously beautiful sunny days, so we decided to explore the foothills! On Wednesday we went to North Table Mountain Ecological Preserve with our friends Rod and Rochelle, and it was covered in wildflowers! It wasn't peak bloom yet, but there were billions of Goldfields, lots of Bitterroots, tons of Meadowfoam, Volcanic Onions, Blue Dicks, Plantains, Bird's-eye Gilia, Poppies, Violets, Popcorn Flowers, Pink Woodland Stars, and some Lupines!  

Bird's-eye Gilia and Goldfields in the WIND! 
Gilia tricolor - Lasthenia californica

The sky was filled with solid gray clouds and a strong wind was constantly gusting from the south, which made photographing the flowers a bit difficult!

Bitterroot and Goldfields 
Lewisia rediviva - Lasthenia californica

North Table Mountain Ecological Preserve is a butte that is a prairie-like expanse of flowering grassland, interspersed with tiny creeks, valleys, and waterfalls! The top of it is capped by an ancient lava flow. It is one of the few places in California that has never been impacted by agricultural crops. Some cattle are allowed to graze there in the wet months, but apparently cause little impact on the native wildflowers. It became an ecological preserve in 1993, when Francis Carmichael, a local rancher, sold 3,315 acres of it to the State of California, to be managed by the California Department of Fish and Game. 

Bitterroot is the largest, showiest wildflower on Table Mountain, and one of my absolute favorites!  This year there were lots of them scattered across the rocky, volcanic mounds throughout the preserve.  The flowers are up to two inches across, with numerous stamens, and a white style with 7-8 branches!  They grow right on the ground, with numerous, thin, succulent leaves 

Prairie Woodland Star 
Lithophragma parviflorum var. trifoliatum

To our delight we came across one clump of beautiful, pink Prairie Woodland Stars!  At 14" tall, they towered above the other wildflowers!  The more commonly seen Woodland Star has tiny white flowers. These flowers were medium sized, about half an inch wide.  We were so lucky to see these uncommon flowers!

Small Creek, Volcanic Mounds, Goldfields and Rusty Popcorn Flowers 
Lasthenia californica -   Plagiobothrys nothofulvus

Right now there are numerous small creeks flowing on the preserve.  The water was brackish and warm to the touch, but no newts were present.  In years past I have seen California Newts, and their eggs in the streams.  The Rusty Popcorn flowers pictured above have yellow centers when they first open, then fade to white as they age.

California Newt and eggs with larvae - 2017 - Taricha torosa

California Newts congregate in the water to mate and lay their eggs.  You can see lots of eggs with tiny white larvae in them in the photo above.  The larvae hatch into gilled aquatic larvae, about an inch long, which transform into little terrestrial newts that crawl onto land when the streams dry up!

Red Maids - Calandrinia ciliata

These lovely magenta Red Maids are another one of my favorites! They are low-growing plants, like a lot of the wildflowers on this butte!

Fields of California Goldfields - Lasthenia californica

California Goldfields were by far the most numerous, blooming wildflowers this week.  In the next few weeks successions of blooms will happen, carpeting Table Mountain in a variety of colors, including orange, blue, purple, white, and magenta.  We plan to come back again soon!


On Monday, my husband and I went down to the South Yuba River State Park to see what was happening. Unfortunately, due to a winter washout/landslide, the main trail along the South Yuba River is closed for this year!  RATS! So instead we hiked up the hill away from the parking lot, and found several kinds of wildflowers in bloom, oak trees leafing out, and Redbud flowering! It was gorgeous!

Pipevine Swallowtail - Battus philenor hirsuta

We also saw several Pipevine Swallowtails flitting through the forests and feeding on flower nectar. These butterflies lay their eggs on Dutchman's Pipe plants. The larvae can ingest the leaves of the Dutchman's Pipe, without being affected by the toxic aristolochic compounds they contain.  In fact the toxins are absorbed into their bodies, and make them unpalatable to predators! The scientific name of the Dutchman's Pipe is Aristolochia californica. It is one of the earliest blooming plants in the oak woodlands.

Springtime trees - Redbud and Oak
Cercis occidentalis - Quercus sp.

Such beauty!
 
Ithuriel's Spear - Lupine sp. - Dutchman's Pipes
Triteleia laxa - Lupinus sp - Aristolochia californica

Some of the wildflowers we saw were Blue Dicks, Popcorn Flowers, Fiddlenecks, Poppies, Buttercups, Iris, Vetch, Ithuriel's Spear, Lupine, and a few Dutchman's Pipes.  


Spring is just starting at the South Yuba River State Park. The grassy green fields will soon be filled with a wide variety of wildflowers.  We'll be back again soon, to enjoy the changing blooms!

What's happening at the Dipper nest?

What new birds have arrived?

Check back next week for the answers to these questions and more!
Your questions and comments are always welcome.  Please email me at northyubanaturalist@gmail.com. Thanks!

Friday, March 29, 2024

Surprising River Sightings!

Common Merganser (male) in the rain - Mergus merganser

We just had a very rainy week, with a total of 3.35" of rain, and it's still raining today. This brings our water year total to 44.46"!  The river is up, at 5.5', and flowing fast at 1600cfs (cubic feet per second). The water is a chilly 40 degrees!  

North Yuba River - 3/26/24

Almost everyday, I linger on our bridge and check out what's happening on the river. This week, to my surprise and alarm there was an adult doe being swept downriver by the fast highwater!  Sometimes her back was showing and sometimes it was totally submerged!

Mule Deer (doe) in the North Yuba River

In less than 30 seconds the doe was carried downriver as far as I could watch her, and then disappeared around the river bend!  WOW!  I kept hoping that she would veer off and get out of the river, but the current must have been too fast.  Hopefully she got out soon after I lost sight of her!  

Mule Deer (doe) in the North Yuba River

I wondered what had made her go into the river. Perhaps she was being pursued by a Mountain Lion or a dog. I even drove down the highway looking for her, but didn't see her. I sure hope she made it.  My neighbor told me that he has seen deer in the river many times during winter!  One time he was upriver where the river gets narrow, fast, and rushes down between huge boulders. He saw a deer enter the river, get flipped over by the current, and washed down river upside down through the boulders!  When the river flattened out, the deer righted itself and then scrambled up the riverbank!  Wow!  They must be way tougher than I thought!

American Dipper nest - American Dipper

On another part of the river I've been observing an American Dipper nest for the past few weeks.  To my surprise and alarm, when I went to check it out yesterday the nest was GONE and the American Dipper was sitting on the ledge all by itself!!!  WHAT???  I had stopped to see the nest about 4 days before, and I remembered that there had been two Common Ravens in the immediate vicinity that day.  The river is way too high and fast for any humans to disturb the nest right now.  So I think that maybe the Ravens investigated the nest to eat the eggs, and knocked it off the ledge in the process!!!  I'm glad the Dipper is still okay despite the destruction of its nest.  It will be interesting to see if it makes a new nest.  I hope it does, but maybe not at such an obvious location!  I also hope the Ravens stay away if it does!!!  Life is tough out there in the wild.

Joubert's Diggins

Local Pond Update

Since it's been too rainy to hike I decided to drive and visit the three local ponds I watch in the winter. At Joubert's Diggins, the usual Buffleheads and Hooded Mergansers were still in residence, but there were some new arrivals including a Common Goldeneye and a pair of Mallards!  I have not yet seen any Wood Ducks there, but maybe they'll show up in the near future.  

Buffleheads (female-male) - Bucephala albeola

There's a population of about ten Buffleheads on these ponds.

Common Goldeneye (female) - Bucephala clangula

Interestingly there was only one Common Goldeneye on the ponds, but it was the first one I've ever seen there!

Hooded Mergansers (female-male) - Lophodytes cucullatus

So far I've only seen this one pair of Hooded Mergansers on the ponds.

Mallards (male-female) - Anas platyrhynchos

Only the Mallards will stay and raise their young here.

Charles Marsh Pond

Surprisingly at the Charles Marsh Pond there was only one duck visible, a female Hooded Merganser!  All winter longer there has been a population of 8 Hooded Mergansers on this pond!

Hooded Mergansers (female) - Lophodytes cucullatus


Wood Duck Pond - 3/28/24

Wood Duck Pond was inhabited by only a pair of Wood Ducks! I felt privileged to see this pair of beauties once again!

Wood Ducks (female - male) - Aix sponsa

Mendocino Silk Moth - Calosturnia mendocino

This super unusual looking moth turned out to be a Mendocino Silk Moth - Calosturnia mendocinoBugguide.net identified it for me!  This is a female and measures 61mm. Males aren't as big as the females, and measure 50mm.  The following information is about their behavior and habitat is from butterfliesandmoths.org 

"Life History: Adults fly in the daytime with a fast and erratic flight. Newly-emerged females fly only after they have mated. Females lay eggs singly or in bunches of 2-6 on the leaves of the host plants. Eggs hatch 1 to 7 weeks later. Loose mesh-like cocoons are attached to stems or branches of the host plants.
Flight: One brood from February-June.
Caterpillar Hosts: Manzanita (Arctostaphylos) and madrone (Arbutus menziesii), both in the heath family (Ericaceae).
Adult Food: Adults do not feed.
Habitat: Chaparral plant communities and the dry edges of redwood forests.
Range: Monterey County, California north through the Coast Range and from Tulare County on the western slopes of the California Sierra Nevada, north through the Cascade Mountains and into southern Oregon."

Sierra Buttes - 3/21/24

Up in the Lakes Basin

Just before the week of rain came in, my friend Diane and I hiked/skied up to Upper Sardine Lake!  There was about 1.5' of packed snow on the roads, so she skied and I walked.  It was a beautiful clear blue-sky day without a cloud in sight. A gorgeous day to be back in the Lakes Basin!

Lower Sardine Lake - 3/21/24

Both of the lakes were still frozen, except for a little thawing on the edge.

Upper Sardine Lake - 3/21/24

The road to Upper Sardine Lake hadn't been driven on
and wasn't packed down. So we punched in the whole way up to the lake and back, and definitely got our exercise!  The view of the lake was well worth the effort! I hadn't been up to the lake in winter since 2021!

Mountain Chickadee - Poecile gambeli

Although there were lots of tracks we didn't see any wild mammals. I did however enjoy a moment with this cute little Mountain Chickadee, whose song was such a familiar "Dee dee dee"!

Table Mountain and the Sutter Buttes

What's happening in the foothills?

What new birds will arrive this week?

Check back next week for the answers to these questions and more!

Your questions and comments are greatly appreciated! Please email me at northyubanaturalist@gmail.com.  Thanks!